Constant supervision by an onsite contractor during all phases of construction is the only way to ensure that work done meets a desired standard of quality and workmanship in this country.
-wiring and piping needs to be run in a chase to be accessible later on
-proper gauge wire and correct circuit breaker for the circuit
-lots of small earthquakes in this area. Proper site preparation is needed before construction starts
-The consistent quality of poured concrete needs to be tested for each truck
etc
The construction industry here bears zero resemblance to the standards and quality foreigners have come to take for granted. There are no electrical, plumbing, structural inspections here so in essence, it is up to you to confirm, that you are getting what you are paying for and that the structure remains sound and serviceable into the future.
It's p.i.a to tear open a wall to fix a leaking plastic pipe or run a new wire. Consider installing the cabling and connections for house wide internet and cable tv during construction rather than needing a hardwired connection in a bedroom or office later on. If you can afford it, minimize the use of rigid plastic plumbing pipes. Ensure the use and accessibility of isolation and shut off valves for everything. Ensure the electrical system is properly grounded. Small things overlooked during construction can be a real problem later on. Insist that the roof is properly strapped to the supporting walls. The list goes on and on, thus the need for a knowledgeable contractor that shares you keenness for the details being onsite while all of this comes together.
A good building starts with the architect and design engineer. The plans need to reflect every aspect and feature of the construction you are hoping to incorporate into the final dwelling and someone to ensure that the plans are followed which is not guaranteed here when workers are left on their own to "get it done".